Traffic control system



Aug. 24, 193 7.

J. L. BIACH El AL TRAFFIC CONTROL SYTEM FiIed April 2:5, 1930 A STREET 4 Sheets-Sheet l ATTORNEYS.

Aug. 24, 1937. J. L. BIACH ET AL TRAFFIC CONTROL SYSTEM Filed April 23, 1930 4 Sheets-Sheet 2 INVENTOR.

BY "m 21%.

M, ATTORNEYS.

J. 'L. BIACH El AL 2,090,619

TRAFFIC CQNTROL SYSTEM Filed April 23, 1930 4 Sheets-Sheet 3 Patented Aug. 24, 1937- PATENT OFFICE TRAFFIC CONTROL SYSTEM John L. Biachand Charles D. Geer, New Haven,

Conn., assignors to The Engineering and R2- search Corporation, New Haven, Conn., a corporation of Connecticut Application April 23, 1930, Serial No. 446,454

25 Claims.

This invention relates to a functionally and structurally improved traffic control system and aims to provide an apparatus of this character capable of use in numerous different associations 5 but primarily intended to be employed at the point of intersection of two or more vehicle lanes such as roadways.

Certain features disclosed in the present case are also disclosed in Patent 2,044,907, issued June 23, 1936, to Frederick G. Kelly, and certain other features are also disclosed in co-pending applications Serial Numbers 73,156 and 446,480, which patent and co-pending applications have a common assignee with the present case, and the claims in the present case are restricted to features not disclosed in the aforesaid patent and co-pending applications.

The features of resetting the condenser charge of the timing condenser by vehicle actuation to extend a right of way signal period in inverse proportion to the speed of the actuating vehicle, and of controlling the charge and discharge of the timing condenser by vehicle actuation are disclosed and claimed in the aforesaid Patent 2,044,907 to Frederick G. Kelly and claims to these features as such are made in the aforesaid patent and these features as such are not claimed in the presentcase.

The periodic cali feature in which right of way 3 is transferred automatically from one street to the other and back at relatively long intervals on each street in the absence of trafiic, subject to earlier transfer of right of way between shorter minimum and maximum intervals by vehicle actuation, is disclosed and claimed in the aforesaid co-pending application Serial Number 73,156, filed April 7, 1936, by Charles D. Geer, which is a division of the aforesaid co-pending application Serial Number 446,480 as originally flied April 23,

1930, and claims to this feature as such are not made in the present case.

The feature of an initial right of way interval on the side street, preceding a side street right of way period which is extendable by trafllc actuation, to provide that traffic waiting on the side street at the start of the right of way period thereon may get into motion by the time the extendable right of way period begins is disclosed and claimed in the aforesaid co-pending applica- 5 tion Serial Number 446,480 of John L. Biach and Harry A. Wilcox, filed April 23, 1930, and no claims to this feature broadly as such are made in the present case.

It is an object of the invention to provide a layout of apparatus furnishing a system operating automatically to expeditiously handle traffic and by means of which danger of accidents will be reduced to a minimum aside from the fact that the functionings of the system will at all times be dependent upon actual traffic conditions. Moreover, bymeans of the present invention, a minimum of apparatus is required and this apparatus will be extremely rugged and relatively simple in construction and when once installed will operate with minimum manual attention and with freedom from mechanical or electrical difficulties over long periods of time.

A further object is that ,of providing an appar'atus of this character, the several parts of which may be manually adjusted to function according to the peculiarities of traffic conditions as actually existing at the point of installation of the system. Accordingly, the same manufacturing specifications may be followed for any desired number of systems and these individual systems may be readily adjusted after installation to meet the conditions then existing aside from the fact that if these conditions change through the course of time, further andsimple adjustments may be made to allow for such changes.

A further object of the invention is that of providing an apparatus furnishing a traflic control system capable of installation to advantage in any number of instances but of particular value at an intersection where vehicle lanes of unequal dignity meet. In other words, this system will be of great utility when installed at a highway intersected by cross streets wherein under ordinary circumstances, the traffic flow along the highway exceeds materially the trafllc flow across the same. w

Another object is that of providing apparatus primarily intended to be employed in connection with traffic control systems and particularly systerns which govern the flow of traffic over roads frequented by automobiles, but which apparatus ,while primarily intended for this purpose is capable of employment'to advantage in other associations wherever it may proveto be of value.

With these and further objects in mind, reference is had to the attached sheet of drawings il lustrating one practical embodiment of the invention, and in which:

Fig. 1 illustrates diagrammatically a street intersection with the system associated-therewitm Fig. 2 schematically indicates a vehicle actuated control forming a part of this system;

Fig. 3 shows one unit of the timer apparatus:

Fig. 4 is a plan view of the timer or control apparatus of the system;

Figs. 5, 6 and 7' are sectional views taken along the lines -5, 6- B, and Il and in the direction of the arrows as shown in Fig. 4;

Fig. 8 is a somewhat diagrammatic view of de- 5 tails of certain of the apparatus as shown in Fig. 5; I

Fig. 9 is a somewhat diagrammatic view of .the layout of apparatus involved in the control and timer unit; and I Fig. 10 represents diagrammatically one of the manual controls for adjusting the factors controlled by the timer.

A self regulating automatical traffic control system embodying our invention may comprise 3 parts; a vehicle actuated control or indicator placed in or at the side of the road; an electrical time limiting control system; and a signal device to indicate right of way to traiiic. A function of the indicating device is such that vehicles approaching on the cross street actuate electrical could be used.

control circuits. These actuationscontrol the operation of the electrical time limiting control system, which in turn controls the right of way device... The right of way device for informing the trafiic in each street when to go and when to stop may be the standard red, yellow and green lights now in general use, but may also be any other convenient or desirable type. The vehicle actuated means may be of several types as here-' inafter mentioned: One means of control actuated by the approaching vehicle may be of a mechanical nature such as a mechanical switch located in or at the side of the street, an electrical contact being made upon passage of the vehicle.

Another control for detecting and recording the presence of an approaching vehicle may be a beam of light projecting across the highway .and received upon a photo-electric or light sensitive cell,

i so that an approaching vehicle causes a fluctuastreet now operates the actuating means and the 1 control mechanism, after showing a suitable warning signal, transfers right of way to B street. 13 street now has the right of way and vehicles approaching on it may cross the intersection. The right of way will be transferred back to A street under either of the following conditions:

Case IAs soon as all traffic has ceased on B street.

Case IIIf traflic continues to approach'on Bstreet at the end of a predetermined period, the Fight of way is transferred back to A street. The various periods -are controlled by suitable timing mechanisms.

Provision to transfer the right of way to A street as outlined under Case I, is accomplished through the use of timing mechanisms which provide suflicient time for the individual B street vehicles to cross the intersection. This timing mechanism is reset toward its starting position each time a vehicle operates the B street actuating means. Hence, if no further vehicles approach on B. street, this timing mechanism will eventually finish timing the period it is set for, and when such time is reached, the right of way is transferred to A street.

To provide for Case II, in which continuous B street traffic must be interrupted, other timing {mechanism is provided which is not reset by vehicles on B street; andwhen it has timed the period it is set for, right of way is transferred to A street.

When right of way is transferred as in Case II, vehicles are on B street which have not had suflicient time to cross the intersection, veven though they have actuated the B street actuating means. The control system is left in such a condition that right of way will eventually be transferred to B street without requiring any additional actuating of the B street vehicle actuated means.

The timing mechanism which is reset by traflic, is so arranged that it maybe reset in accord with the speed of'the vehicle causing the resetting. Thus the time or protection period given each vehicle is commensurate with the speed of the vehicle. In this manner, no vehicle receivesan unnecessarily long protection period, avoiding needless delay in the highway.

Whenever right of way is given to the highway,

it must remain showing on the highway for at least a certain minimum period before it may again be transferred to the cross street. This is accomplished by providing a timing mechanism which starts timing as soon as right of way is given to the highway and prevents transfer to the cross street until it has timed the period it is set for.

'If several vehicles have passed the actuating means while being given the stop signal, some time will elapse, after they have been given the right of way signal, before the last of said vehicles gets into motion.. For this reason, an

additional timing mechanism is provided which introduces an additionalinitial protection period at the expiration of which the resettable protection period begins. This time is sufficient to allow the waiting vehicles to get into motion.

In order to provide for the occasional shifting of right of way to the cross street, even though there are no waiting vehicles thereon, is accomplished by providing a timing mechanism which begins to time as soon as right of way is given to the highway, and unless right of way is transferred to the cross street previously, due to vehicles approaching on the cross street, transfers right of way when it has finished its timing period. While we have described above a self regulating auto-' matical trafiic control system embodying our invention, and have shown that this invention may comprise three interconnected parts, we now describe in detail the construction of onecomplete and specific system embodying our invention.

Referring to Fig. 1 of the drawings, there is shown a complete self regulating traffic control system applied to intersecting streets A and B. A represents the highway, and B'the cross street. Vehicle actuated control means are located in 'the cross street only, and are indicated by numerals l and 2. The signal means in this particular embodiment is indicated by 3 and contains red and green electrical lamps, reflectors and/or lenses visible from either direction on A street, but not visible on B street; red and green electric lamps, reflectors and/or lenses visible from either direction on B street, but not visible on A street;' a yellow electric lamp, reflector and/or lens visible from either direction on street, and a yellow electric lamp, reflector and/or lens visible from either direction on 13 street. The electrical time limiting control is indicated by 4. The lines connecting vehicle 5 actuated means I and 2, the time limiting control 4, and the signal 3 indicate controlling circuits. Thus the vehicle actuated devices control the time limiting control 4, and the time limiting control 4 controls the signal 3.

Fig. 2 shows schematically one form of vehicle actuated control consisting of a ramp 5 hinged at 6 and forced into the elevated position by spring 1. The top surface of the ramp may be substantially on the level of the street. When the wheel of a vehicle passes over the unit, the weight of the vehicle depresses ramp 5 causing contacts 8 and 9 to be pressed together, closing a circuit between wires l and II. When the wheel leaves ramp 5, spring 1 forces the ramp 20 into an elevated position separating contacts 9 and 9 and breaking circuit between wires Ill and H. The vehicle actuated devices land 2 are connected in parallel.

The time limiting control uses several timing mechanisms. One embodiment of such a timing mechanism is shown schematically in Fig. 3. When a source of voltage supply is connected between wires 12 and I3, current flows through adjustable resistance l4 and condenser i5. Thus the voltage of the supply is applied to condenser 15 through resistance l4, and the voltage of the condenser begins to build up at a definite rate determined by the size of the condenser, the resistance l4 and the voltage of the supply. Shunting condenser I is a circuit including a glow tube 16 and a relay I8. The glow tube comprises a bulb containing a suitable gas into which electrodes l1 extend. This tube has such a characteristic that it is normally non-conducting, but when the voltage across its terminals reaches a certain critical or threshold value, the gas ionizes and becomes a good electrical conductor and will not become non-conducting again until the voltage across its terminals has dropped considerably below the critical ionizing voltage. .The voltage of ,the supply is greater than the critical voltage of tube l6. When the voltage across the condenser is built up to the critical voltage of the tube, the tube. suddenly becomes conducting, 50 causing current to flow momentarily from condenser i5 through tube l6 and relay [3, causing relay l8 to operate momentarfly. This effects'a momentary contact between armature 23 and contact l9 and thus momentarily closes circuit 55 between wires 2i and 22.

The interval elapsingbetween the application of the supply voltage to wires 12 and I3, and the operating of relay I3, is the period timed by the mechanism. By suitable adjustment of re- 60 sistance 14, any desired interval may be obtained.

The above description shows only the fundamentals of the timing mechanism and the details may be varied considerably as will be explained later.

In addition, while relay It has been shown as 65 closing one circuit, it may obviously close several circuits, or open circuits. One example of this general type of'timing mechanism is'shown in Patent No. 1,909,471 issued May 16, 1933, to Frederick G. Kelly, Jr. a

Before describing the details of the time control mechanism, one portion of it, as shown in Figs. 4, 5 and. 6, will be reviewed. Referring to Fig. 4, there is shown a shaft 23 rotatively mounted in bearings 24. Keyed to shaft 23 is the 75 toothed wheel 25. Referring to Fig. 5, there is shown the toothed wheel mounted on the shaft 23. Also mounted on the shaft 23, and freely movable with respect thereto, are members 26, one on each side of wheel 25. The ends of the two members 26 are connected together as at 21 and 26. Magnet 29, the terminals of its winding being indicated by wires 30 and 3|, attracts core 32 when energized. By means of link 33, core 32 is connected to members 26; It will thus be appreciated that, whenever magnet 29 is energized, the two members 26 ,are rotated in a counter-clockwise direction. Spring 34 is at-- tached to rivet 21, and consequently, whenever magnet 29 is deenergized, the two members '26 are rotated in -a clockwise direction. The connecting pin 26 also carries live pawl 35, which is forced against toothed wheel 25 by spring 36. Dead pawl 31, mounted on the frame 38 at 39, also is forced against the'toothed wheel 25 by a spring 40. The pawl 31 prevents any counterclockwise motion of toothed wheel 25, and therefore, whenever magnet 29 is energized, the rotation of members 26 causes live pawl 35 to slip past wheel 25. Motion of members 26 would be adjusted so that pawl 35 moves past and engages with the next tooth of wheel 25. When magnet 29 becomes de-energized, spring 34 rotates members 26 in a clockwise direction, and pawl 35, being in engagement with wheel 25, rotates wheel 25 in a clockwise direction. An adjustable set screw 4| limits the clockwise motion of members 26 to the amount of one tooth of wheel 25. As wheel 25 moves in a clockwise direction, pawl 31 slips past the next tooth of wheel 25 and at the end of the motion, engages this next tooth. The mechanism is returned to the position shown in Fig. 5, except that wheel 25 has been rotated through the angle subtended by one tooth. It

will thus be appreciated that the successive energizing and de-energizing of magnet 29 causes a notching motion of wheel 25. Since shaft 23 is keyed to wheel 25, shaft 23 rotates in synchronism with wheel 25. In this particular embodiment, there is shown a wheel 25 having 18 teeth.

Mounted upon shaft 23 are a series of spaced cams 42 keyed to shaft 23. Fig. 6 shows in detail a side elevation of one of the cams. It will be noticed that the cam is circular in shape, and

carries 3 equally spaced projections 43. Mounted upon frame 35 is a member 44 carrying circuit 7 makers 45. The details of these circuit makers are shown in Fig. 6. It will be noticed that they may consist of two flat strips 46 and 41. The two strips are separated by an insulator 45-, and they are separated from member 44 by an insulator 43. .-.They are supported onmember 44 by means of screws 50. Member 41 has a V shaped projection 5i, and each member 46 and 41 carries contact 52 and 53. Both member and member 41 are preferably of springy material, and member .41 is tensed so that the edge of the V shaped projection 5| always rests against cam 42. when resting against the circular part of cam 42, member 41 is in a down position causing contacts 52 and 53 to separate. But-when, during the cycle of revolution of cam 42, projection 43 moves under the projection 5|, member 41 is' raised bringing contacts 52 and 53 into contact. In this manner circuit betweenleads 54 and 55 is made during the time projection 5i rests upon" projection 43. It will furthermore be noticed that circuit between wires 54 and 55' is made 3 times per revolution of cam 42. As described above,

motion of cam 42 is not continuous but proceeds in a series of steps, 18 per revolution. The projection 63 can be so constructed that duringone position of cam 42; contact between 52 and 59 is made, and during the next succeeding 5 positions, contact between 52 and 59 is broken. Similarly, by making projection 93 subtend twice the portion of the surface of cam 92, as shown in Fig. '1, contact between 52 and 59 may be made during four positions and broken during the next succeeding two positions. Obviously, a similar change in construction would allow contact between 52 and 53 to be made in any desired positions.

Fig. 8 shows in still greater detail, one end of member 29 and connecting pin 27. It will be noticed, as in Fig. 4, that pin 27 extends beyond member 26 in the form of projection 79. When magnet 29 is de-energized and spring 39 has moved member 29 as far as it will go in a clockwise direction, projection I3 disengages spring I9,

moving its contact I5 out of engagement with the contact I6 carried by. spring II, and circuit between wires I8 and I9 is broken. When magnet 29 is energized, projection I9 presses against spring I4 as soon as member 28 begins to move,

and circuit between wires I8 and I9 is again established. As soon as member 26 is moved in a counter-clockwise direction as far as it will go, this being adjustable by limiting the travel of core 32, projection I9 engages spring 99 and throughinsulating post 8i engages spring 82. Contacts 83 and 84 carried by springs 99 and 82 respectively, move into contact with contacts 85 and 86 carried .by springs 8'I and 98 respectively, completing circuit between wires 89 and 99 and between wires 9i and 92. When magnet 29 becomes deenergized, spring 39 immediately begins to return members 26 to their former position. As soon as the clockwise motion of member 29 begins, circuit between wires 9i and 92 is broken and circuit between wires 89 and 99 is also broken. Just as member 26 reaches its completely de-energized position, projection I9 moves out .of engagement with spring 14, and circuit between wires l8 and 19 is broken. While. in the illustrated embodiment the contacts separate incident to spring action, it will be understood that this action might be supplemented by positive engagement with the pin 13 or its equivalent so that as'the latter moves to one'position, a positive'removal of one contact from engagement with the other is assured.

Fig. 9 shows the complete wiring diagram of the control mechanism, and I2 represents the cams in developed form; one-third of one revolution being shown, the other two-thirds being mere duplications. It will be noticed that there are I6 cams and numerals 56 through II represent con tacts. operated by these cams. The scheme of representation shown under numeral I2 is as follows: In one position, for example, A, contacts 51, 69, 62, 93 and 61 are closed. If magnet 29 is now energized and de-energized, the cams will be notched or shifted to position B. Contacts 62 and 63 remain closed. Contacts 51, 69, and GI are now open, but contacts 58, BI, and B9 are closed. The operation is similar as the cams are notched successively to positions C, D, E and F. In this figure the notching magnet 29 is again indicated and whenever energized, operates the 3 switch members 93, 94, and 95 which represent schematically the 3 circuit closers shown in Fig. 8. Armature 93 is the o e which is closed as soon as the motion ofmem r 26 starts and 94 and 95 are the two which are-closed at the end of the motion of member 26. The circuits closed are designated by the same numerals as in Fig. 8. Elements 96 and 9] represent relays, and whenever either retiming to be interrupted while the signals remain illuminated in any desired position of the cam shaft. This switch may be operated manually or by remote control means and may be used in cooperation with switch IIII to provide complete manual control of solenoid 29 and thus of the signals. Eitherof these switches can be operated by atraffic authority or otherwise, at will.

As will appear later, when all trafic has ceased on street B, the apparatus will eventually come to rest in position F. In this position contact 59 is closed lighting the A street green signal, and contact 59 is closed, lighting the B street red signal. Thus, the right of way is being given to the highway and vehicles may proceed on that street. At the same time, contact is closed allowing current to flow from wire 98 through contact 99, resistance I95, wire I96, wire I97, wire I99, condenser I99 and wire 99, and the voltage ofcondenser I99 begins to build up at a rate determined by the value of resistance I95. Assume that this resistance is adjusted so that condenser I99 is charged up to the critical voltage of tube II9 in thirty seconds. However, even though condenser I99 reaches the initial voltage of tube I I9, tube II9 does not become conducting because its discharge circuit is open at contact 99 and in addition'is open at armature III and contact I92. Thus, the system remains inactive and right-of way continues to be shown to the highway.

If a vehicle approaches on the cross street oper ating one of the vehicle actuated control devices located there, circuit between wires I9 and II closes contact between armature III and contact II 2, completing the circuit shunting condenser I99 through wire I29. Tube II9 becomes conducting and the energy stored in condenser I99 discharges through relay 9'I' operating it momentarily. This closes contact between armature I99 and contact I9l, energizing magnet 29 which in turn rocks the notching mechanism consisting of members 26. 9 As soon as core 32 has been fully attracted, circuit between wires and 99 is made which shunts resistance I2I directly across the terminals of condenser I99. Resistance I2I is of a very low value, its only purpose being to prevent arcing'when switching mechanism 94 closes. This allows any energy remaining in condenser I99 to be dissipated in resist- A street yellow signal, and contact 60 is closed, lighting the 13 street yellow signal. At the same time contact 69 is closed insuring that the discharge circuit of condenser I09 shall remain 5 closed regardless of subsequent action to relay I ll. At the same time contact 61 is closed allowing current to flow from wire 93 through contact 61, resistance I22, wire I23, wire I24, wire I25,

condenser I26 and wire 99, and in a similar man- 10 ner the voltage of condenser I26 begins to build up at a rate determined by the value of resistance I22. Assume that the period required is 2 seconds. At the end of two seconds, condenser I26 reaches the critical voltage of tube I21 and the 15 energy stored in condenser I26 discharges through tube I21 and relay 96. Relay 96 operates, closing circuit between armature I03 and contact I06, energizing magnet 29, which in turn rocks the notchlng mechanism consisting of 20 members 26. When members 26 have moved to their extreme energized position, switching device 95 closes circuit between wires 9I and 92, placing resistance I29 directly across the terminals of condenser I26. Resistance I28 is similar to resistance I2I and performs the same function for condenser I26 that resistance I2I performs for condenser I09. The remaining energy of condenser I26 being dissipated in resistance I29, relay 96 becomes deenergized, deenergizing 30 magnet 29-which allows members 26 to again move forward the cams, which shift from position A to position B.

In position B, contact 50 is closed lighting the A street red signal, and contact 6I is closed lighting the B street green signal. The right of way is now being given to B street and the vehicle which approached there may cross; In position B, contact 69 is closed and current flows into condenser I26 through resistance I29, and condenser 40 I26 reaches the critical voltage of tube I21 in 3 seconds. At' this moment, tube I21 again becomes conducting and the notchlng operation proceeds in the very same manner previously described advancing the cams from position B to position C. In moving from position B to position C, there is no change in the signal lights. Contacts 50 and SI remaining closed. Contact 62, however, is opened, which breaks the locking circuitof relay Ill which drops to .its deener- 50 gized position. In addition, contact II is closed,

and since relay Illis deenergized, current flows from wire 98 through resistance I30, contact I3I, armature I32, contact II, wires I23, I26 and I25, condenser I26 and wire 99, and similarly the volt- 55 age of condenser I26 begins to build up at a rate determined by resistance I30. Assume that this resistance is set so that condenser I26 builds up to the critical voltage of tube I21 in '1 seconds. Assuming that no further cars approach on the 60 cross street, then after '1 seconds, condenser I26 will discharge through tube I21, performing the very same steps of the notchlng operation described previously. This notches the cams from position C to position D.

(35 In position D. contacts 51 and 60 are again made, lighting both the A and B street yellow lights. In addition, contact 68 is made which closes the charging circuit of condenser I26 through resistance I33. Assuming that resist- 7 ance I33 is set to charge condenser I26 up to the critical voltage of tube I21 in 2 second th condenser I26 will discharge after 2 seconds, and the notchlng operation will proceed again as described previously, shifting thecams from'posi- 75 tion D to position E.

In this position, contacts 56 and 59 are made, lighting the A street green signal and B street red signal, and the right of way has returned to the highway. At the same time contact I0 is made which charges condenser I26 through resistance I34 as previously described. Assume that the period timed, as determined by the setting of resistance I34, is S-seconds. .Then after 5 seconds, the advancing operation will again proceed, as previously described, and the cams will be moved from position E to position F. We have reached the condition described at the beginning and charging of. condenser I09 starts, contact 65 being made. But after condenser I09 has reached the critical voltage of tube H0, it does not discharge'through said tube because the discharge circuit is open, as described previously.

We have thus described the operation of the device assuming that only one car approached on the cross street. It will be noticed thatafter right of way has been showing on the highway for a certain length of time, right of way is immediately callable to the cross street, should a vehicle approach there. But if a vehicle should approach on the cross street at any time after the cross street has lost right of way, and before right of way has been given to the highway for a certain minimum length of time, relay H4 will operate and lock in, closing the discharge circuit of condenser I09, but, no discharging of condenser I09 can take place until it has been charged to the critical voltage of tube H0, and this cannot take place until right of way has been showing .on the highway for the certain minimum length of time governed by the value of resistance I05.

If right of way has been transferred to the cross street in response to a vehicle approaching there, and a second vehicle approaches on the cross street before the end of the '7 second period which is timed in position C, relay H4 will operate, causing armature I32 to touch contact I35,

which shunts resistance I36 across the terminals of condenser I26, at the same time interrupting the charging circuit of condenser I26. Referring again to Figure 2, it will be noticed that the length of time circuit between wires I0 and II remains closed depends entirely upon the length of time the wheel of the vehicle is on ramp 5. And this again depends entirely upon the speed of the vehicle. The slower the vehicle is traveling, the longer is this length of time, and the faster the vehicle is traveling, the shorter is this length of time. Consequently, adjustable resistance I36 is shunted across the terminals of condenser I26 for a period of time dependent entirely upon the speed of the vehicle operating relay I I4. If the vehicle is moving slowly, this time will be long and practically all of the energy stored in condenser I26 will be dissipated in resistance I36,-

and thus when the energizing circuit is re-established, charging of condenser I26 will start with practically nostored energy in the condenser, andthe time required to charge it up to the critical voltage of tube I21 will be practically 7 seconds. If the vehicle is traveling fast, the time of discharge, and consequently the amount of discharge will be small. Thus, when the energizing circuit is re-established, charging of condenser I26 will start with some remaining stored energy, and the period timed will be the period necessary to charge condenser I26 from the voltage existing at that moment to the critical voltage of tube I21. The time period will be shorter by-the amount of time that would have been necessary to charge condenser I26 from zero voltage to the voltage to which it had been reset. Thus it appears that the amount of reset depends upon the length of time the energizing circuit is interrupted.

The above is the action of the apparatus if the energizing circuit is always interrupted when condenser I26 has been charged to some particular voltage. In practice, as will appear later, the interrupting of the energizing circuit may occur at all sorts of different voltages. Considering the operation of the device more in detail, it will appear that the actual amount of discharge, while dependent upon the length of time the energizing circuit is interrupted, also depends upon the voltage to which condenser 926 had been charged whenthe energizing circuit was interrupted. Thus for a resettingimpulse of a certain length of-time, the amount of reset is proportional to the voltage existing at the moment when resetting started. It thus appears that while the first vehicle on the cross street receives a full 7 seconds, subsequent vehicles receive a period which depends upon their speed and, consequentand will there discharge through tube I21, notchly receive protection periods which correspond to the speed at which they, are traveling. The faster the vehicle travels, the less the reset and consequently the less is the time given the vehicle. But, the faster the vehicle travels, the less time it needs.

The above would be the actionif succeeding vehicles continually approach just before condenser I26 is about to discharge. In practice, traflic rarely approaches in just that way. For example, the second vehicle'may approach within a second or two from the time the first approached; and, if there were no resetting at all, the second vehicle might receive or 6 seconds in which to cross the intersection, which might be ample. The apparatus automatically takes care of just such a condition. If the second vehicle approaches, say after 2 seconds, condenser I26 will have been energized for only 2 seconds and the voltage it has reached will be quite small. Consequently, the amount of reset will be very small, and the additional time given above the time it would receive were there no reset at all, would be small. If the second car approached after 5 or-6 seconds, the voltage of condenser I26 would be large, the amount of reset large, and the additional time given, large. Thus there is provided a mechanism which very efficiently provides a protection period in accord with" the speed of the vehicle. I As soon as traflic ceases to approach on B street, condenser I26 will be permitted to charge to the critical break-down voltage of tube I21 ing or advancing thecams to position D, and from then on the operation is as described above.

Should vehicles approach continuously on B street, continually resetting condenser I 26, right of way would remain indefinitely on the cross street to the disadvantage of the highway unless some limitation is imposed upon the length of time the cross street may retain right of way. It will be noticed that in position C, contact 64 is closed which allows charging current to flow into condenser I09 through resistance I31. Assume that resistance I31 is so adjusted that condenser I09 will reach the critical'voltage of tube II 0 in 20 seconds. This condenser is not reset by ap-' .proaching vehicles, and if trafiic continues at the end of 20 seconds, condenser I09 will discharge through tube 0, operating relay 91 which enera'oeaeie gizes magnet 29, and the mechanism notches to position D as described previously." The difference is that relay 9! also operates armature 138 which touches contact I39 which allows current to flow through relay H4, operating it. The energizing circuit made at armature I38 is only momentarily closed and relay II4 would not remain energized, (its locking circuit being broken at contact 62) were it not for contact device 93 which is made as soon as notching mechanism 26 begins to move. This completes circuit between wires I8 and 79 which provides a temporary locking circuit. Contact 62 is made in position D and as a matter of fact, is made slightly before solenoid 29 becomes fully de-energized, and is so adjusted that contact 62 is made just before circuit between wires 18 and I9 is broken, maintaining relay H4 in an energized position. Thus, while some vehicles have lost right of way before they have had sufficient time to cross the intersection, the system remains in such a condition that without requiring any additional actuation of the B street vehicle actuated device, right of way will revert to B street at the end of the highway right of way period.

It will be noticed that right-of way is being given-to B street in position B although the resettable timer has not begun to operate. This period, in this case 3 seconds, is the period provided to allow one or more vehicles which may be waiting on B street to get into motion, and presumably the last of such waiting vehicles is actually in motion when the mechanism notches the cams to position C.

If no vehicles are waiting on B street, right of way will be given to the highway and may remain there indefinitely, thus preventing pedestrians from crossing the highway. It is desirable to .provide a system which will occasionally shift right of way to the cross street even though there are no vehicles waiting thereon, stopping highway traflic and allowing pedestrians to cross the highway. This is accomplished through contact 66 which is made in position F. This charges condenser I26 through resistance I39, and this resistance is adjusted so that condenser I26 is charged to the critical voltage of tube I21 in 2 minutes. This notches the cams to position A and from then on they automatically advance themselves through the succeeding positions. Of course, should vehicles approach while cams are in position C, they will reset condenser I26, as described previously. But if no vehicles at all approach, rightof way will shortly be returned to the highway and highway trafiic may proceed.

In describing the operation of the system, we have-shown the device as exhibiting the signal lights in the usual sequence, namely, green, yellow, red, yellow, green. It frequently is desirable to omit the showing of yellow when the shift is from red to green, and continue to show a red light while a yellow light is being given to the street which is losing right of way. This can be ure 6, it will be noticed that if a second contact ting position 3, in which case, of course, only 15 teeth per revolution of the cams would be required. Position E is provided for certain reasons which will be explained later. Suffice it to say at the moment that if position B is omitted, position E may be conveniently omitted also, and thus only 12 teeth per revolution would be required. In a similar way any desired amber period may be omitted by constructing the cams without that particular position. It is to be noticed that one revolution of the cams provides three complete signal cycles. The reason for choosing this particular arrangement will appear later, but as a matter of fact the cams can be constructed so that two complete cycles are given per revolution, or anydesired number.

Contacts 62 and 03 both remain closed during 5 positions. The only difierence between the two is that the two contacts are three positions out of step. In other words, contact 62 is broken three positions ahead of the time contact 63 is broken, which is, of course, one-half a cycle, a cycle being six positions. Referring now to Figstructure I 42 is mounted at the bottom of the cam, one cam can be used to operate two contacts, the only difference being that the lower contact is one-half a cycle out of step with the upperfcontact. It now appears that instead of using one cam, for contact 62, and another cam for contact 63, by arranging the contacts as shown in Figure 6, one cam can be made to do the work of two. It will furthermore be noticed that earns 64 and 65 can be paired in the same fashion, also contacts 66 and I I, contacts 61 and 68, contacts 69 and 10, contacts 56 and 58, contacts 59 and Bi, and contacts 51 and 60. Although the number of contacts is not changed, only one-half the number of cams need be used. The number of positions per cycle in thiscase is six, and therefore the upper and lower contacts of each cam can be displaced by one-half cycle, and if, in addition, the number of cycles per revolution is an odd number, the upper and lower contacts maybe mounted parallel. This is the purpose of position E, namely, to provide an even number of positions per cycle. Of course "as long as the number of cycles per revolution is an odd number, the contacts may be mounted parallel. If only one cycle per revolution were used, the notching mechanism would have to advance the cams 60 degrees per step, which in-' troduces mechanical difficulties. With three cycles per revolution, the amount advanced per step is only 20 degrees, which can be accomplished easily. Afurther interesting feature of this device is the way in which any one time period may be adjusted. Consider, for example the minimum right of way-period given to the highway. This is controlled by resistance I05. Fig. 10 shows the details of this resistance which,

, of course, may be duplicated in each instance-if desired. It will be noticed that resistance I05 may be made up of several small resistors I06 placed in series. It is a well known fact that if the supply voltage remains constant and the condenser does not change, then the period required to reach the critical voltage will be proportional to the charging resistance. Each individual resistance may be of such a value that if it alone is in the charging circuit, 10 seconds are required to charge the condenser to the critical voltage. Then if two are in series, 20 seconds will be required. If three are in series, 30 seconds will be required, and so on. By providing an ordinary rotary switch I01, which can be moved on to any one of several contacts I08, each of which has a tap wire I 09 leading to the junction between the individual small resistors I06, the time period may be varied by simply moving this switch manually by means of a dial which may be marked with the various settings. Obviously, the increase from step to step need not be 10 seconds, but can be any other desired value.

It will be understood from the above description of the apparatus and its operation thru a cycle that the time element represented by Figure 3 or any other suitable timing element is employed successively in different positions of the cam shaft to time the interval before the cam shaft is shifted to its next position. The cam operated contacts or other suitably operated contacts upon each shift of the shaft from one position to another connect a suitable operating circuit including appropriate resistance as illustrated in this embodiment of the invention to control the time period of the timer. Thus the condenser timer of Figure 3 serves as a single timing element or timing means which is employed for different types of timing functions and various independently adjustable time intervals thru the cam contacts which it causes to operate at the end of each of its time intervals. The solenoid and ratchet mechanism or other suitable cam shaft operating means resets this single timing element each time it operates at the completion of a time interval to prepare it to start its next time interval the moment that the cam shaft has been shifted into the next position. In the present embodiment two such single timing elements are employed in order to care for the two different timing functions concurrently active particularly in positions C and F of the cam shaft but it will be clear to those skilled in the art that the employment in accordance with the invention of a single timing unit to operate a multi-circuit controlling mechanism, which in itselfbesides controlling work circuits also changes the functions of the timer and provides a new operating circuit for it with independent adjustment of its time interval in successive positions of the circuit controlling mechanism. provides a. very flexible time control mechanism. Especially with an electrostatic timer of the type disclosed in this embodiment or any suitable modification or substitute for the same which will be apparent to those skilled in the art, a time controlled switching mechanism is made available in accordance with this invention which minimizes the number of moving parts and per mits such parts to be made of simple, rugged construction and also provides a wide range of convenient time adjustment.

From the foregoing, it will be seen that by means of the present invention, a traffic control system is provided which will function so:

1. That in the absence of traffic on the cro'ss street, right of way is normally shown in favor of the highway.

2. That a vehicle approaching on the cross street transfers right of way to the cross street.

3. That a vehicle which has passed an actuating means is protected against opposing traffic for a period of time sufficient to permit said vehicle to pass the intersection of the traflic lanes.

4. That continuous traffic on the cross street will not i'etain right of way to the disadvantage of the highway for more than a certain period.

5. That when a vehicle is not given immediate right of way, the system will be left in such a condition that right of way will be given to it as soon as traflic conditions permit.

6. That when a vehicle has right of way taken from it before it has had sufiicient time to cross the intersection, the system will be left in such a condition that right of way will re-turn to the delayed vehicle as soon as traflic conditions permit.

7. That whenever right of way is given to the highway, it must remain there for at least a certain length of time. i

8. That periodically right of way shifts to the cross street even though there be no vehicular trafflc on the cross street, in order to allow pedestrians to cross the intersection.

9. Ihat the signal means may be disconnected from the trafiic actuated means and be operated manually.

10. That a warning signal may be interposed between right of way and stop signals.

11. That each vehicle approaching a' right of way signal is protected against opposing traflic for a period commensurate with its speed.

12. That if one or more vehicles, after passing the actuating means, do not receive. right of way immediately they will be protected against opposing trafiic when they do receive right of way, for an additional period of time sufllcient to allow the last of the waiting vehicles to get started.

It will be understood that by means of the present invention, it is only necessary to provide vehicle actuated controls in a single vehicle lane. Moreover, as shown, the right of way when once transferred to the highway remains in favor of the highway for a suiiicient period of time to clear up or at least relieve any accumulation of traflic on the highway incident to the transfer of right of way to the cross street. This will occur despite the fact that vehicles even after the expiration of the maximum timing period in favor of the cross street are still awaiting right of way on the latter. However, the timing mechanism provided to achievethis result might obviously be 5 modified in certain respects in order that its improved construction might be accommodated to other types of traiiic control systems.

Moreover, it will be seen in connection with the factor of safety and control provided by the present system and viewing the same from one angle that not alone does the system take into account the fact that the vehicles approaching the intersection must be accorded a time interval to negotiate the intersection additional to preceding vehicles which have actuated the control, but the resetting by means of which this factor is allowed for will be proportional to the speed of the vehicle. Viewing another aspect of the invention, it will be observed that the system takes into account in the case of a line of vehicles awaiting right of way and all of which have actuated the control that the latter vehicles of this group-incident to getting into motion and allowing for proper spacing between vehicles-will need a period of time additional to the minimum required in the case of a single .vehicle which is in continuous motion from the time it actuates the control until it completely negotiates the intersection. Also, in the absence of transfer of right of way from the highway to the cross street-as would occur normally if there were no vehicles awaiting right of way on the latter-the system will take into account the needs of pedestrians in order periodically to interrupt the right of way on the highway. It will be additionally understood that while the present system provides a warning at the time of transfer-of right of way, that this warning need not necessarily be accorded in the specific manner shown, although preferably an amber or equivalent signal will be furnished. For example, a blank period might in certain instances serve this purpose while in other instances, if a red or Stop indication were simultaneously accorded, both vehicle lanes at the time of transfer of right of way; this might be adequate.

In connection with the manual operation of the system under point 9 aforemade, it will be understood that this is achieved by, opening switch M0 and thus disconnecting the timing mechanism from the lights. Thus the lights may be operated manually by simply pressing push button l ii which upon each functioning energizes magnet 29 thus advancing the cams through their cycle and in so doing transfer right of way from one vehicle lane to the other.

. Obviously any number of changes and rearrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

Having described our invention, what we claimas new and desire to secure by Letters Patent, is: 1. A tramc control system for two interfering traflic lanes including in combination signalling means for according and interrupting right-ofway in said lanes, a timer connected to said signalling means to control the same, trafiic-actuated means in one of said lanes, said timer including means, when conditioned operating for transferring right-of-way to the lane of said traffic-actuated means in response to actuation of said traffic-actuated means and automatically re-transferring right-of-way to the second lane thereafter, means for automatically transferring right-of-way from said second lane a predetermined maximum period after it is accorded, means for maintaining right-of-way in said sec-. ond lane for a predetermined minimum period less than said maximum and at the end of said minimum period so conditioning the second means for immediately transferring right-of-way only after said minimum and before said maximum in response to actuation by traiiic in the lane of said traflic actuated means.

'2. A trailic control system for two interfering traflic lanes including in combination signalling means adapted to accord and interrupt right-ofway to said lanes, a traflic-actuated device in one of said lanes, a timer connected to said sig nalling means and to said traffic-actuated device to control said signalling means in cooperation with said traffic-actuated device, said timer including means, when conditioned functioning in response to operation of said trafiic-actuated device to cause said signalling means to accord right-of-way to the lane of said trafiic-actuated device for a minimum period and thereafter to accord right-of-way to the other lane and also including two timing devices for timing the pe-- riod of right-of-way on said other lane, one timing device providing a minimum period, immediately after which it conditions the second means so that another operation of said trafllc-actuated device can cause transfer of right-of-way from said other lane to the lane of said device, and the other timing device providing a maximum period of right-of-way longer than said minimum after which maximum the right-of-way is automatically transferred to the lane of said traflic-actuated device in the absence of actuation of said device.

3. A trafilc control. system for two interfering traflqc lanes including in combination signalling means for according and interrupting right of way in said lanes, a timer connected to said signailing means to control transfer of right of way by the same, trafiicactuated means in one of said lanes only, control means forming a part of said timer and acting when operable to cause ferring right of way to said second lane within a predetermined maximum period thereafter, timing means to maintain right of way on said second lane for a predetermined minimum period and thereupon to make said control means operable for such response to actuation and means forming a part of said timer to cause automatic transfer of right of way to said-first laneafter a predetermined maximum period of right of way in said second lane longer than the minimum in the same lane and during which there is no actuation on said one lane.

4. A system for controlling trafiic, including signalling means to be visible to traflic approaching over either of two intersecting lanes, a timer connected to said signalling means and operating cyclically to transfer right of way indication by said signalling means from one lane to the other lane after the right of way has endured in said I one lane for a maximum period of time, means forming a part of said timer to retransfer right of way from said second lane to said first lane after right of way has endured in the second lane for 'a certain period of time, said system includinga traflic actuatable controller to be disposed solely for use by trafiic approaching the intersection over the second lane and connected to said timer to cause transfer of right of way from said first lane to said second lane, and means forming a part of said system and preventing transfer of right of way from the first lane to'the second lane and in response to controller actuation until the right of wayin .the first lane has endured for, at least a minimum period less than said maximum, said last named.

some'ans including a timing device comprising a condenser, means for charging the condenser, means connectible to said condenser and acting responsive to a predetermined charge when connected to said condenser to cause transfer of u right-of-way from said first lane by said signal and means responsive to controller actuation to connect said charge responsive means to said condenser.

5. A traiilc control system for two interfering go trafllc lanes including in combination signalling means to accord .and interrupt right of way in said lanes, trafllc actuated means in one of said lanes only, a time controlled switching'mechanism ior normally operating said signalling means .5 to accord right of way cyclically for a minimum period to the lane of said tramc actuated means and for a maximum period to the other lane in the absence of actuation of said trafiic actuated meansnneans when conditioned operable upon 7 actuation of said trafllc actuated'means while right of way is accorded to said other lane to interrupt the normal cyclic' timing and substantially immediately cause transfer of right of way to the lane of said traflic actuated means, and

15 means forming a part of said time controlled switching mechanism to prevent such interruption and transferuntil right of way has been accorded to said other lane for at least a predetermined minimum period and then to condition the third means to permit such interruption and transfer thereafter up to said maximum period.

6. A trafiic control system for two interfering tramc lanes including in combination signalling means to accord and interrupt right of way in said lanes, tramc actuated means in one of said lanes only, a time controlled switching mechanism for normally operating said signalling means to accord right of way cyclically for a minimum period to the lane of said trafilc actuated means and for a maximum period to the other lane in the absence of actuation of said traffic actuated means, means when conditioned operable upon actuation of said trafilc actuated means while right of way is accorded to said other lane to interrupt the normal cyclic timing and substantially immediately cause transfer of right of way to the lane of said trafiic actuated means, and means forming.-a part of said time controlled switching mechanism to prevent such interruption and transfer until right of way has been,

accorded to said other lane for at least a predetermined minimum period and then so condition thethird means until right of way is transferred from said other lane, further means forming a part-of said mechanism and operable upon actuation of said traflic actuated means while right of way is accorded to the lane of the latter to interrupt the normal cyclic timing and prolong right of way onthat lane.

7. A-trailic control system for two interfering trafllc' lanes including in combination signalling means to accord and interrupt right of way in said lanes, traflic actuated means in one of said lanes only, a time controlled switching mechanism for normally operating said signalling means to accord right of way cyclically for a minimum periodto the lane of the said trafiic actuated means and for a maximum period to the other lane in the absence of actuation of said. traflic actuated means, means when conditioned operable upon actuation of said tramc actuated means I while right of way is accorded to said otherlane to interrupt the normal cyclic timing and substantially immediately cause transfer otright of way to the lane of said traflic actuated means, and means forming a part of said time controlled switching mechanism to prevent such interruption and transfer until right of way has been accorded to said other lane for at least a predetermined minimum period and then so condition the third means until right of way is transferred from said other lane, further means forming a part of said mechanism and operable upon actuation of said traflic actuated means while right of way is accorded to the lane of the latter to interruptthe normal cyclic timing and prolong right of way on that lane,additional means form- 'ing a part of said mechanism to prevent prolongation by such tramc actuated means of right of way in its lane beyond a predetermined maximum period of right of way.

8. A trafiic control system for two interfering trafiic lanes including in combination sig nailing means adapted to accord and interrupt right-of-way to said lanes, a tramc-actuated device in one'of said lanes, a timer connected to said signalling means and to said traiilc-actuated device to control said signalling means in cooperation with said'trai'nc-actuated device, said ,timer including means functioning in response removal of right-of-way from said other lane,

and the other timing device providing a maximum period of right-of-way' longer than said minimum, after which right-of-way is automatically transferred to the'lane of said traflic-actuated device, said first timing device comprising a condenser, means for charging said condenser, and control means when operable acting responsive to a charge exceeding a predetermined value on said condenser to terminate said minimum period and cause interruption of right of way in said other lane, and further means functioning in response to actuation of said traffic-actuated device to make said control means operable.

9. A trafllc control system for two interfering trafllc lanes including in combination signalling means adapted to accord and interrupt right-ofway to said lanes, a timer connected to said signalling means to control the same, .said timer including timing means functioning upon according right-of-way on one lane to maintain it in said lane for a predetermined period, said timing means comprising a condenser, means for charging said condenser, control means connectible to-said condenser for causing interruption of right-of-way upon the charge on said condenser exceeding a predetermined value, a trafflc-actuated device in the other lane, and means to connect said control means to said condenser upon operation of said traflic-actuated device. 1.0. A tramc control system for a plurality of interfering traific lanes including in combination signalling means adapted to accord and interrupt rightof way to said lanes, a time con-- trolled switching means for controlling said sig nalling means to transfer right of way between said lanes and to accord right of way to one lane at av time, timing means for controlling said switching means and functioning when right of way is accorded to one lane to maintain it in said lane for a predetermined minimum period before transfer to a second lane, said timing means comprising a condenser, means for'varying the charge on the condenser from an initial value toward ,a flnalyalue, control meanscon- 55, nectible to said condenser for causing operation of said switching means to cause the signalling means to transfer right of way from said onelane to the second laneupon the charge on said "condenser reaching a predetermined value between said initial value and said final value, traflic actuated means in said second lane, and means to connect said control means to said condenser .upon operation of said trafllc actuated means.

" 11. A tramc control system for two interfering ,traiiic lanes including in combination signalling means adapted to accord and interrupt right-ofway to said lanes, a timer connected to said signalling means. to control the same; said timer including timing means functioning upon according of rlght-of-way to one lane to maintain it.

in said lane for 'a predetermined minimum period,

said timing means comprising a condenser, a

- charging circuit connected to said condenser, an electronic tube having a threshold conducting voltage and a relay in series and connectible to said condenser to operate said relay upon the charge on said condenser exceeding the said threshold voltage, means responsive to operation of' said relay to cause said signal to interrupt 5 right-of-way in said one lane, trafllc-actuated' means in the other lane, andmeans to connect said tube and relay to said condenser in response to operation of said traffic-actuated means. 12. A traflic control system including in com-- 10 bination signalling means for display n ndications for the control of traffic at an intersection of tra'mc lanes, means connected to said signal to control the same, a source of electrical current supply, a condenser, a plurality of circuits l5 connectible to said source of current supply and including means to charge said condenser at different rates, means for selectively couplingone of said circuits to said condenser to charge the same, traflic-actuated means in one of said 2 indications for the control of 'traflic insaid lanes;

traflic-actuated means in one of said lanes, time controlled means connected to said signalling means and to said traflic-actuated means for causing said signal to indicate right-of-way to'the lane of said trafllc-actuated means in response to actuation of said traffic-actuated means,said

- time controlled means including a condenser, a 40 condenser charging means, a condenser discharging means, means connected to said condenser and acting responsive to a predetermined charge on said condenser to operate said signal to interrupt said right-of-way and to change the time 45 rate of charge of said condenser, and means functioning upon operation of said traflic-a'ctuated means while said right-of-way is accorded to its lane to operate said condenser discharge ing means so as to extend the period of rightof- 6 way.

A 14. In a trafllc signal control apparatus for' control of right of way at the intersection of a plurality of trailic lanes having a signal and 1 means for operating said signal responsive to- 55 trafiicin at least one lane, the combinationof switching mechanism having a plurality of different positions for operatingthe signal to display the diiierent control indications, a condenser, means normally operable for varying the on charge on said condenser from an initial level toward a final level, means responsive to the charge on said condenser reaching a predetermined level between said initial and final levels to operate said switching mechanism from one posi- 5 tion to another, reset means actingwhen operable to render ineffective said normally operable charge varying means and to vary the'charge on said condenser .away from saidflnal level and toward said initial level, and means forming a 70 part of gaid switching mechanism to connect said reset means for operation responsive to actuation of the trailic, responsive means when said switching means is in one position in which iic responsive means and to disconnect said means at other times.

15. Traffic signal control apparatus for providing a cycle 01' right-,of-way control fora plu- 5 rality of interfering trafl'lc lanes having means operable responsive to trafllc in at least one lane said apparatus comprising in combination mechanism adapted to be operated through a cycle to accord right of way successively to said lanes,

a single timing device for timing the operation 0L said mechanism in certain parts of such cycle, A

part of the cycle to the other and concurrently operate said switches to change between such circuit means. I

16. A trafllc control system for interfering trafllc lanes including in combination a signalling means for according and interrupting right-oiway i'n'said lanes, a'timer connected to said signal to control the same, traihc actuated means in one of said lanes and connected to said timer.

said timer including a rotary switching mechanism having a plurality of timed positions for operating the signal to accord and interrupt right-oi-way in the lanes, a timing device con nected with said mechanism to govern the time it is in each of such positions and to operate said mechanism i'romeach position to the next at the end of such time, said switching mechanism 00- operating with said timing device to cause ac- 40 cord of right-of-way through two of such positions to the lane of said traflic actuated means in responseto actuation of such means and to provide a predetermined minimum period of such accord of right-of-way in the last named lane in one of such positions and then to shift to an im-' mediately following position in which it provides a further right of way period in saidlast named a lane, and means forming a part of said switching mechanism for rendering only said further period variable by actuation of said trafllc actuated means during said further period.

17. In an electrical timing apparatus for controlling-work circuits, the combination of a condenser, one circuit for connecting said condenser to a source of power to charge the condenser at a certain time rate, a second circuit for connecting said condenser to the same source of power for charging the condenser at a diil'erent time rate, switching means connected with'said circuits, and no means responsive to said condenser being charged 'by one of said circuits to a predetermined extent to operate said switching means to connect the other circuit. I

' 8. In an electrical timing apparatus for con- 05 trolling work circuits the combination of a condenser, means including a circuit and 'a switch therein for connecting said condenser to a source of power to charge the condenser at a certain time rate, means including a-seoond'circuit and w switch therein for connecting said condenser to the same source of power for hm the condenser at a diflerent time rate, switching means for actuating said switches to connect one of said circuits at a time to said-condenser and means 75 connected to said condenser and operatinglwhen the condenser is charged to a predetermined extent to operate saidswitching means.

19. In a timing apparatus, the combination of an electrical current supply, a condenser, a plurality of circuits connectible to said condenser to charge the same at different time rates, switching means forming a part of .said circuits, a shaft and means operated thereby for operating said switching means to successively connect and disconnect said circuits upon rotation of said shaft, an electronic tube having a threshold conducting voltage, a relay connected to said tube and operable upon said tube becoming conducting, said relay and tube being connected across said condenser, and means operated by operation of said relay-to rotate said shaft.

20. In a timing apparatus the combination of a source of electric power, a condenser, an electronic tube adapted to pass current only when the voltage acrossits terminals exceeds a certain critical value, a relay in series with said tube in shunt with said condenser and adapted to be operated when said tube passes current responsive to voltage across the condenser exceeding said critical value, a plurality of control circuits each including a resistance and a circuit closer and arranged when closed to be connected between said supply and said condenser to vary the'voltage thereon 'over a time interval, a shaftand means operated thereby cooperating with said circuit closer and operable during one phase'of rotation of said shaft to close one of said control circuits and open the others'and during another phase of rotation to open said one circuit and close one ofthe others, and means operated by. operation of said relay to rotate said shaft from one phase to another.

21. In an'apparatusfor the'control of work v circuits tliru atime cycle of operations, the combination 01 an electrical power supply, a condenser, a plurality of control circuits including switching means and connectible to said condenser to vary at different time rates the charge on the same from an initial level toward a'final level, mechanismhaving a series of more than two positions corresponding to such cycle of operations and adapted to cyclically operate said switching means successively to connect and disconnect said control circuits in said series of positions, an electronic tube connected to said condenser so .;as to pass substantial current only upon the charge on said condenser reaching a certain level,

.a relay connected to said tube and condenser and operated by said tube passing substantial current and means operated by operation of said relay control circuits for said condenser and including means to vary the charge on said condenser'at diiierent time rates from an initial value to a diiierent predetermined value, means including certain of said contacts for selectively coupling one of said control circuits at a time to said condenser to charge the same in the several positions, and means operating upon the charge on said condenser reaching said predetermined value to opmeans will couple another of said control circuits to said condenser.

23. In a timer for operating work circuits in a sequence of operations at time periods, the coinbination of a rotary switching mechanism having more than two positions and switches operated.

switching means from said one position to the 7 15 next position, and means forming a part of said charge responsive means and operating assaid switching means is shifted to reset said condenser charge to its initial value to prepare the condenser for timing the next period. 20 24. In a controller for operating work circuits through a sequence of operations, the combination of a rotary step-by-step switching means having a plurality of contact positions, a single timing device adapted to be operated from a 25 normal starting condition over a time interval to a time interval completion condition to determine a time period for said switching device in .each of such positions, said timing device adapted to be reset to its starting condition from any 30 other condition including said time completion condition, a plurality of operating circuits for said timing device and including means in the circuits operated by said switching means to 017- erate said timing device to time periods of difierent time lengths in the several positions, means controlling work circuitsrthrough a time cycle of operation, the combination of switching means, a rotatable shaft and means operated thereby to operate said switching means, said shaft having a plurality of operating positions, a ratchet wheel mounted on said shaft, a solenoid and means operated thereby for engaging said ratchet wheel to rotate said shaft from one position to another, an electric condenser, means for varying the charge on said condenser over a time period from an initial value to a different predetermined value to determine the time interval insuch positions,

means operating responsive to the charge on said condenser reaching said predetermined value to operate said solenoid, and meansoperated by operation of said solenoid to, restore the charge on said condenser substantially to said initial value.

JOHN L. BIACH. CHARLES D. GEER. 

